Remember, no one owes you anything. No one has to dispose of their perfectly working systems just because you think they should.

I have a 64bit CPU with 8GB of RAM and, guess what, I'm running a ... 32bit Linux distro (with PAE). Why? Because I don't have any applications which magically work a lot faster in 64bit mode. Because I don't want to have a 32bit compatibility layer because I need to run Skype and Wine applications.

A few months ago I compared 32bit and 64bit versions of Firefox. At least in the V8 test made by Google 32bit Firefox is ... 25% faster than 64bit Firefox (the same system, the same kernels/libraries/etc.)

PAE isn't good enough to run matlab on certain processes as it can consume in excess of 5Gb + of RAM, with PAE apps can only address 4Gb.